In the field of motor vehicle engineering by means of internal combustion engines, it is generally known that the fuel supply in the overrun mode of the internal combustion engine is interrupted in order to reduce the fuel consumption of the internal combustion engine. In this context it is generally known to initiate the fuel supply again if a predefined restarting rotational speed or an idling rotational speed of the internal combustion engine is reached. This restarting rotational speed occurs at approximately 1000 rpm in current series-manufactured vehicles. The consumption of the internal combustion engine can generally be reduced further if the restarting rotational speed is reduced further, since as a result the motor vehicle can be operated for longer in the overrun mode without a fuel supply. It is thus disadvantageous here that in the case of strong deceleration of the motor vehicle, such as for example in the case of emergency braking, the injection of the internal combustion engine is not started quickly enough and the rotational speed of the internal combustion engine drops below a critical rotational speed and cannot be started again through the fuel supply alone.
DE 102005027615 A1 discloses a method and a device for controlling an internal combustion engine in which a setpoint rotational speed at which the fuel supply is resumed again with an overrun cutoff is increased if a vehicle brake is activated. It is disadvantageous here that not every braking process can cause the internal combustion engine not to start up again, that the setpoint rotational speed is unnecessarily increased and as a result the fuel consumption cannot be reduced significantly.
It is also known from DE 102007010295 A1 to increase the setpoint rotational speed during an overrun cutoff if a brake pressure limiting value is exceeded. It is disadvantageous here that as a result of the detection of the brake pressure emergency braking is under certain circumstances detected too late and the setpoint rotational speed is increased too late, with the result that unintentional switching off of the internal combustion engine can occur.